I may have misread this part, sorry in advance.

I create a game, give it a name, set players to 15 levels and make it public. I go up levels because I am bored waiting, so I open up the "Create Group" window, click EDIT Group, change the level requirements, re-enter game name and click edit group... I don't need to make another catacomb.

This is pretty much cancelling your group listing, Name, player level requirements, even Guild Only if need be. Is this what you are referring to?

yeah more or less. I guess you can just change the lvl requirement to 1 and have the same end-result. Unless one of the 50 people online just happened to be the same level haha